Methods :
Fifteen LHON subjects with G11778A ND4 mutation received a single intravitreal injection of rAAV2/2-ND4 in their worse seeing eye. Three subjects were included in each dose-escalation cohort (9x109, 3x1010, 9x1010, 1.8x1011 vg/eye) and 3 in an extension cohort (9x1010 vg/eye).